Interventional techniques for removing disease such as atherosclerotic plaque, thrombus and other types of material forming obstructions and partial obstructions from internal body lumens or cavities using interventional catheters are well-established. Interventional catheters may employ operating heads that break down and/or remove occlusive material using mechanical structures such as cutter assemblies, abrasive materials and/or shaped tools, excision devices, ablation instruments employing modalities such as RF, laser or radiation-induced ablation modalities, ultrasound, fluid jets or fluid agitation and the like. Other types of interventional catheters may provide fluid infusion and/or aspiration alone, or in combination with another diagnostic or treatment modality. Many of these systems involve placement of a guiding catheter and/or guide wire prior to introduction of the interventional catheter, facilitating navigation of the interventional catheter to the target operating site and manipulation of the interventional catheter at the target site over the guide wire.
Many material removal devices and interventional catheters incorporate mechanical aspiration systems to remove the ablated material from the site and some systems incorporate or are used in conjunction with other mechanisms such as distal filters for preventing removed material from circulating in the blood stream. Some interventional catheter systems incorporate or are used in conjunction with a fluid infusion system providing delivery of fluids to an interventional site. Interventional catheter systems may also incorporate or be used in conjunction with imaging systems and other types of complementary and/or auxiliary tools and features that facilitate desirable placement and operation of the system during an interventional procedure.
Interventional catheters are generally mounted to controller housing drive mechanisms, fluid manifolds and management systems, and the like, at a proximal end of the catheter. Some types of interventional catheters employ a single operational and control component interfacing with and mounted to the interventional catheter. In devices that interface with a single operating and control component, system operating components may be housed in the control component and user interface controls for operating the catheter and operating head are provided on the operating and control component. Various control features for activating and operating the interventional catheter, its aspiration and/or infusion systems, and/or its operating head may be provided. Status indicators, system read-outs and operating information may also be provided on interventional catheter operating and control components.
Some interventional catheter systems may employ both a console-type controller that houses non-disposable components such as pumps, drive systems, electrical, electronic, vacuum and fluid control systems, and the like, as well as another intermediate control device that provides operator interfaces and control options and, in some cases, feedback information. The intermediate control device is typically located at or near a proximal end of the interventional catheter, and may be positioned within or close to the sterile field during a procedure. Interventional catheter systems employing both a console-type controller and an intermediate control device are described, for example, in PCT International Publication WO 2008/042987 A2, the disclosure of which is incorporated herein by reference in its entirety. Patients may also be monitored during an interventional procedure using separate or integrated systems, such as fluoroscopic or other visualization systems, vital sign monitoring systems, and the like.
Many interventional catheter systems are used in combination with a guide wire, which is navigated to a target intervention site and then aids safe navigation of the interventional catheter, over the guide wire, to the target site. The guide wire also facilitates positioning and movement of the interventional catheter over the guide wire at the target interventional site during the interventional procedure. When interventional catheter systems are employed as atherectomy or thrombectomy devices, for example, a guide wire is generally introduced into a patient's vasculature and advanced until its distal end is positioned at a location distal to the occlusion and the target intervention site. The interventional catheter is then advanced over the guide wire to a location just proximal to the occlusion. During an intervention, the distal end of the interventional catheter is generally advanced and retracted over the guide wire through the interventional site in distal and proximal directions, respectively, at least once and sometimes repeatedly, to remove occlusive tissue. Many other types of interventional catheter systems also involve translation of an interventional catheter over a guide wire prior to and/or during an intervention.
The guide wire generally traverses an internal guide wire lumen in the interventional catheter assembly and is generally routed into and through a controller or housing provided at the proximal end of the interventional catheter, exiting the controller at another location. A guide wire brake or clamp is generally provided within or in association with the controller, or in association with a proximal end of the interventional catheter, permitting the operator to clamp the guide wire in a fixed position. The guide wire is generally clamped following positioning of the guide wire and interventional catheter at the target interventional site, and during manipulation of the interventional catheter over the guide wire during an intervention.
When the guide wire is clamped following positioning of an interventional catheter in proximity to an interventional site and the interventional catheter is advanced distally over the clamped guide wire, the relative displacement of the catheter over the clamped guide wire in a distal direction exposes an equivalent length of guide wire between the proximal end of the catheter and the guide wire clamp. The excess guide wire exposed at the proximal end of the catheter as the interventional catheter is advanced distally generally accumulates within the controller or housing, or elsewhere between the proximal end of the interventional catheter and the guide wire brake. As the interventional catheter is retracted (i.e., moved proximally over the guide wire), the excess guide wire length accumulated at the proximal end of the interventional catheter is taken up and additional guide wire length is exposed, again, at the intervention site distal to the interventional catheter. This dynamic change in the relative positions of the guide wire and interventional catheter, resulting in variable lengths of exposed guide wire between the proximal end of the interventional catheter and the guide wire brake, is generally difficult to accommodate and presents guide wire management challenges.
Guide wires are relatively stiff along their longitudinal axes, and they tend to deform or kink or bend unacceptably when constrained in a space too small to accommodate the full length of the guide wire. Interventional catheter controllers mounted to the proximal end of an interventional catheter are generally relatively compact and thus provide limited space to accommodate the changes in guide wire length between the proximal end of the interventional catheter and the guide wire clamp as the interventional catheter is advanced distally over the guide wire. Because there is generally limited space for accommodating changes in guide wire length between the proximal end of the interventional catheter and the guide wire brake, operation of an interventional catheter over a guide wire for any substantial length generally requires repeated releasing and reclamping of the guide wire as the operating head is advanced and retracted during an intervention. This is particularly problematic when an interventional site, such as a lesion in a blood vessel, is relatively long. Readjustment and reclamping of the guide wire during the procedure as the operating head is repeatedly advanced and repeatedly retracted, complicates and prolongs the interventional procedure, which is undesirable and generally increases the risks of the intervention.
U.S. Pat. No. 7,713,231 discloses an extendible, telescoping guide wire support mounted in an intermediate controller device housing some of the interventional catheter operating systems. The telescoping guide wire support adjusts between a shorter, substantially folded condition and a longer, substantially extended condition to support the guide wire as the catheter and/or operating head are advanced and retracted over a clamped guide wire at the interventional site. This arrangement improves guide wire management during the operation of advanceable operating heads, but it still requires repeated releasing and reclamping of the guide wire when the interventional site, e.g., the length of a lesion, exceeds the length of the telescoping guide wire support device and the space allotted for the support device in the controller housing.
While considerable prior art exists relating to guide wire design, methods of using guide wires with interventional catheters, and guide wire brakes and clamps, there remains a need for improved performance of interventional catheter assemblies over guide wires and improved integration of guide wire brakes with interventional catheter assemblies, as well as for improved devices and methods for manipulating, adjusting, limiting or otherwise managing the relative movement and/or positioning of guide wires relative to interventional catheters and/or controllers during an intervention. Improved guide wire integration and improved management of guide wire positioning; relative to an interventional catheter assembly and/or controller result in faster, safer and more effective catheter-based interventional treatments.